An impacted tooth is tooth that fail to erupt into the dental arch within the expected time after completely root formation.
Indications for Extraction:
Localized or Generalized Neuralgias of the Head.
Production of Caries. 4- Decreased Bone Support of Second Molar.
5- Obstruction of Placement of a Partial or Complete Denture.
6- Obstruction of the Normal Eruption of Permanent Teeth.
7- Provoking or Aggravating Orthodontic Problems.
8- Participation in the Development of Various Pathologic Conditions.
9- Destruction of Adjacent Teeth Due to Resorption of Roots.
Steps of Surgical Procedure
The surgical procedure for the extraction of impacted teeth includes the following steps:
1. Incision and reflection of themucoperiosteal flap
2. Removal of bone to expose the impacted tooth
3. Luxation of the tooth
4. Care of the postsurgical socket and suturing of the wound
The main factors for a successful outcome to the surgical
procedure are as follows: Correct flap design, which must be based on the clinical and radiographic examination (position of tooth, relationship of roots to anatomic structures,
Ensuring the pathway for removal of the impacted tooth, with as little bone removal as possible. This is achieved when the tooth is sectioned and removed in segments, which causes the least trauma possible.
Classification of impaction of mandibular third molars
According to Archer (1975) and Kruger (1984). (1Mesioangular, 2 distoangular, 3 vertical, 4 horizontal, 5 buccoangular, 6 linguoangular, 7 inverted)
According to Pell and Gregory (1933): a according to the depth of impaction and proximity
to the second molar.
Class A: The occlusal surface of the impacted tooth is
at the same level as, or a little below that of, the second molar (Fig. 7.15 a, 1).
Class B: The occlusal surface of the impacted tooth is at the middle of the crown of the secondmolar or at the same level as the cervical line (Fig. 7.15 a, 2).
Class C: The occlusal surface of the impacted tooth is below the cervical line of the second molar (Fig. 7.15 a, 3).
b their position according to the distance between the secondmolar and the anterior border of the ramus of the mandible.
Class 1: The distance between the second molar and the anterior border of the ramus is greater than themesiodistal diameter of the crown of the impacted tooth, so that its extraction does not require bone removal from the region of the ramus (Fig. 7.15 b, 1).
Class 2: The distance is less and the existing space is less than the mesiodistal diameter of the crown of the impacted tooth (Fig. 7.15 b, 2).
Class 3: There is no room between the second molar and the anterior border of the ramus, so that the entire impacted tooth or part of it is embedded in the ramus (Fig. 7.15 b, 3).
Types of Flaps:
Two types of flaps may be used when surgically removing impacted mandibular third molars: the triangular and the envelope flap. The choice depends on the evaluation of the various data pertaining to the case (e.g., depth of impaction, position, etc.).
Triangular flap: The incision for this type of flap begins at the anterior border of the ramus (external oblique ridge) with special care for the lingual nerve and extends as far as the distal aspect of the second molar, while the vertical releasing incision is made obliquely downwards and forward, ending in the vestibular fold.
Horizontal (envelope) flap:
The incision for the flap also begins at the anterior border of the ramus and extends as far as the distal aspect of the second molar, continuing along the cervical lines of the last two teeth, and ending at the mesial aspect of the first molar.
Anesthesia. Anesthesia in cases of impacted mandibular third molars is achieved by: inferior alveolar nerve block, buccal nerve block, lingual nerve block, and local infiltration for hemostasis in the surgical field.